The present invention relates to bandages, wound dressings, surgical dressings, transdermal dressings, topical dressings and the like. While not so limited, the invention is especially suited for use in dressings which include a vapor and gas permeable polymeric film having an adhesive coated surface.
Various forms of bandages or dressings have heretofore been proposed, including dressings formed from transparent polymeric films which are coated with a biocompatible or hypoallergenic pressure-sensitive adhesive. Such dressings have many uses. For example, they are used for skin closures, wound covers, pressure sore covers and intravenous fluid site covers.
A typical film type dressing is formed from a polyurethane film which is permeable to oxygen and water vapor. Commercially available polyurethane films usable as dressings have moisture vapor transmission rates between 15 and 80 grams per 100 square inches per 24 hours as determined by ASTM Test E 96 at 100.degree. F. and 90 percent relative humidity. The films have a thickness of from 1 to 3 mils.
Various types of pressure sensitive adhesive are used to retain the film on the skin of the patient. The well-known skin contact adhesives are copolymers of 2-ethylhexyl acrylate and vinyl acetate. Water based adhesives and hot melt adhesives may also be employed. The adhesive is coated or spread onto the film at a thickness so as not to impede the gas vapor permeability characteristics of the film. Generally, the adhesive coated film is applied to a silicone-coated carrier, release sheet or liner. Typically, the dressings are supplied in different sizes in individually sterilized packages. Examples of various transparent film-type wound or surgical dressings may be found in U.S. Pat. No. 4,413,621 entitled FILM DRESSING and issued on Nov. 8, 1983 to McCracken et al; U.S. Pat. No. 4,370,981 entitled PROTECTIVE DEVICES AND METHOD and issued on Feb. 1, 1983 to Sanderson; U.S. Pat. No. 3,426,754 entitled BREATHABLE MEDICAL DRESSING and issued on Feb. 11, 1969 to Bierenbaum et al; and U.S. Pat. No. 2,949,443 entitled SURGICAL DRESSINGS and issued on Aug. 16, 1960 to Merriam et al.
Difficulties are experienced with the application of such thin, adhesive coated transparent film dressings. The film is thin and flexible and will stick to itself. Unless care is taken during application, a smooth dressing which will stay in place is not achieved. In order to overcome some of the problems in separating the film from the release sheets or liners, various proposals have been made. In one proposal, a composite bandage includes a release sheet, an adhesive coated film and a paper framing. The release sheet is peeled off, exposing the adhesive surface. The bandage is held at the paper framing, and the film is applied to the site. The paper framing or border must then be removed or peeled off the film and the film smoothed against the patient's skin. In other forms, adhesive-free tabs are provided to grip and position the dressing. After the film dressing is applied, the tabs are cut or torn from the film.
A need exists for a wound or surgical dressing of thin, adhesive coated film type which is easily applied to the skin and by which the difficulties and problems experienced with even, smooth and secure application are eliminated.